A testing system includes: a bilinear polarized antenna for receiving and dividing a circularly polarized radio wave associating with a horizontal and a vertical polarization path of an object-to-be-tested into a first and a second high frequency signal; a phase retarder for delaying a phase of the first high frequency signal by 90 degrees to form a first high frequency signal with a phase delay of 90 degrees; a power splitter for receiving or synthesizing the first high frequency signal with the phase delay of 90 degrees and the second high frequency signal; and a high frequency signal transceiver for measuring power of the first high frequency signal with the phase delay of 90 degrees and the second high frequency signal and determining states of the horizontal and vertical polarization paths of the object-to-be-tested based on the power. Therefore, the testing system can speed up testing of the object-to-be-tested.